Immunogenicity of inactivated vaccines prepared with parainfluenza viruses type 1 and type 3, administered experimentally by nasal or oral route.

The inactivated vaccines prepared with parainfluenza viruses type 1 and type 3, administered to mice by nasal or oral route, either as monovalent preparations in succession or as bivalent associated preparations according to the experimental models used, imparted a significant protection against the infection with the homologous active viruses. The routes of administration of vaccines, nasal and oral, which make equal demands upon the immune secretory serum and cell system, as well as the alternative of inactivated preparations for active virus vaccines are discussed.